Sundance peered into the distance from behind the large boulder. “Tell them that,” he said, almost ashamed to disrespect the wisdom of his mentor.

Butch turned around to see for himself. He couldn’t believe what he saw. “They’re beginning to get on my nerves,” he said with a tinge of anger. Then, after a pause, added with heartfelt curiosity, “Who are those guys?”

“Those guys,” as they referred to in the 1969 classic Butch Cassidy and the Sundance Kid, were Pinkerton Detectives. In the film, the Pinkertons chase the outlaws after their gang had robbed the Union Pacific train. Butch Cassidy identifies one of them as Joe LeFors. No matter how hard they try, they can’t escape the posse.